Electric stowing system for vehicle seat

ABSTRACT

The invention provides a seat stowing system for stowing in a floor recess ( 16 ) a seat ( 15 ) with a seat back ( 22, 23 ) tipped forward to fold it against a seat cushion ( 21 ). The stowing system ( 20 ) includes a seat back forward-tipping mechanism for automatically tipping the seat back forward and a swinging mechanism ( 30 ) for automatically swinging the folded seat back and the seat cushion as one. The seat back forward-tipping mechanism and the swinging mechanism are drive-controlled by a control unit, and the operation of stowing the seat in the floor recess is thus made electric.

TECHNICAL FIELD

This invention relates to an electric stowing system for a vehicle seat,for electrically stowing in a stowage recess formed in a floor, andreturning, a rear seat disposed rearmost among a plurality of rear seatsarrayed behind a front seat.

BACKGROUND ART

There are those vehicles which, so that they can carry 6 to 7passengers, have behind a front seat a plurality of rear seats made upof a front-row rear seat, which is a first rear seat, and a back-rowrear seat, which is a second rear seat. For example, as disclosed inJP-UM-A-5-40029, a stowing structure for a vehicle seat is known inwhich a back row seat is folded down to increase the space inside apassenger compartment. This stowing structure will now be described onthe basis of FIG. 42 and FIG. 43A through FIG. 43C.

Referring to FIG. 42, a vehicle seat stowing structure 500 isconstructed so that normally a second rear seat 501 is disposed at theback of a car as shown with solid lines so that a passenger 502 can beseated, but for example when a large item of luggage is to be loadedinto the passenger compartment 503 the second rear seat 501 can bestowed in a floor recess 504 formed behind it.

This vehicle seat stowing structure 500 will be described on the basisof FIG. 43A through FIG. 43C, using as an example the case of stowingthe seat in the floor recess 504.

In FIG. 43A, to stow the second rear seat 501 of the vehicle seatstowing structure 500 in the floor recess 504, first, the seat back 506is tipped forward as shown with an arrow to fold it down against theseat cushion 507.

In FIG. 43B, a headrest 508 is removed from the seat back 506 foldeddown against the seat cushion 507 and stowed in a headrest stowage part509 (see FIG. 43C) provided inside the passenger compartment 503. Then,the seat cushion 507 is swung rearward about a support shaft 510 alongwith the seat back 506 as shown with an arrow.

In FIG. 43C, the seat cushion 507 and the seat back 506 (the second rearseat 501) are stowed in the floor recess 504.

Here, the second rear seat 501 itself is relatively heavy, and for thesecond rear seat 501 to be swung rearward in the vehicle body and stowedin the floor recess 504 by hand a large manipulating force is necessary.Also, when the second rear seat 501 is stowed in the floor recess 504,it is necessary for the second rear seat 501 to be unlocked as it isswung by hand.

Because of this, stowing the second rear seat 501 in the floor recess504 is relatively troublesome, and in this point there has been room forimprovement.

As means for ameliorating this problem, it is desirable for the effortrequired of the operator to be reduced by for example stowing the secondrear seat 501 in the floor recess 504 electrically.

However, for the second rear seat 501 to be stowed in the floor recess504 electrically, it is necessary for the second rear seat 501 to beprovided with a drive source, and to provide a control unit forcontrolling this drive source.

The control unit must for example receive a signal from an operatingswitch and transmit a drive signal to the drive source, and whenreceiving an attitude signal from the second rear seat transmit asuitable signal to the drive source on the basis of that signal. Tosupply a suitable signal of this kind to the drive source, the controlunit may be relatively large. Consequently, it has been generallyconsidered that the control unit should be mounted on the vehicle bodyside.

However, when the control unit is mounted on the vehicle body side,because it is distant from actuators mounted to the second rear seat,harnesses connecting actuators and sensors to the control unit becomelong, and the laying of the harnesses may become troublesome.

In addition, as a result of a harness being led out from the second rearseat, when the second rear seat is being stowed, the harness led out maybe caught up by the second rear seat. Therefore, to realize electricstowing of the second rear seat, there is a need for the harnessesconnecting actuators and sensors to the control part to be made short,and for the harnesses to be prevented from being caught up by the secondrear seat.

Also, when stowing of a seat is made electric, because it is necessaryfor the seat back and the seat cushion to be folded together and swungwithin a small passenger compartment, if the process is just simply madeelectric, because luggage and the like will sometimes become sandwichedbetween the seat and the vehicle body, there is a risk of the electricstowing system breaking down.

Accordingly, there is a need for the effort of the seat stowing task tobe reduced; for the harnesses to be made short; for the harnesses to beprevented from being caught up when the seat is being stowed; and forthe sandwiching of luggage and the like to be prevented.

DISCLOSURE OF THE INVENTION

The present invention provides an electric stowing system for a vehicleseat for folding down a seat back against a seat cushion and swingingthe seat cushion and the seat back together and stowing the seat in afloor recess positioned behind the seat, the system including: seat backforward-tipping means for automatically tipping the seat back forward tofold it against the seat cushion; swinging means for automaticallyswinging the forwardly tipped seat back and the seat cushion as one andstowing them in the floor recess; and a control unit for controlling theoperation of the seat back forward-tipping means and the swinging means.

Because in the seat stowing system of this invention the seat back istipped forward automatically like this, an unlocking actuator forunlocking the seat back can be made small, and the actuator can beincorporated into the seat. Also, because a large torque is needed toswing the folded seat, the swinging means for swinging the seat ismounted on the vehicle body side. Consequently, without sacrificing thesize of the seat, it is possible to make the seat stowing operationelectric, and the effort required of the passenger for the seat stowingoperation can be reduced.

In the invention, preferably, when the seat stowed in the floor recessis being returned to its sitting position, at a position where the seatcushion has swung to a predetermined angle a reclining lock of the seatback forward-tipping means is unlocked so that the motor driving forceis applied only to the seat cushion. After the seat cushion has beenreturned to a position where it has swung for example 50° with respectto the seat back, because the seat back is in the sitting position, anoperation of pulling the seat back upright becomes unnecessary.

Also, preferably, the electric stowing system of this invention furtherincludes a seat operating switch for ordering operation of the seat backforward-tipping means and the swinging means, and the seat operatingswitch is disposed behind the seat cushion. In this case, the switch canbe operated easily from the tailgate of the vehicle. Even if luggagebecomes sandwiched between the tailgate and the vehicle body opening,the seat does not malfunction.

Preferably, the control unit controls the seat cushion and the seat backto be operated automatically on the conditions that an automatictransmission of the vehicle is in a Park position, or a parking brake isoperating, and a tailgate is open. In this case, a passenger can onlyperform the seat stowing operation when the tailgate is open.

Preferably, the seat back forward-tipping means is incorporated into theseat back or the seat cushion. In this case, the electric stowing systemcan be made compact.

Preferably, the control unit is incorporated into a central part of theseat cushion which is off of any sitting position. That is, the controlunit can thereby be disposed in the proximity of the seat backforward-tipping means and the swinging means, and multiple harnessesconnecting the seat back forward-tipping means and the swinging means tothe control unit can be made short, and the harnesses can be laidwithout trouble. Also, by the control unit being incorporated into theseat cushion, it becomes possible for the harnesses also to beincorporated into the seat cushion. Therefore, it is not necessary forthe harnesses to be led out from the seat cushion, and it will nothappen that when the seat cushion is swung the harnesses are caught upby the seat cushion. Furthermore, because the control unit isincorporated into a central position off of the sitting positions of theseat cushion, passengers can sit on the seat cushion without sittingabove the control unit, and there is no impairment of the sittingcomfort of the passengers.

Also, preferably, the stowing system of this invention further includesa dome-shaped cover member for covering the upper face of the controlunit, and the cover member is incorporated into the seat cushion. Inthis case, outside loads such as the weight of a passenger sitting onthe seat cushion or the weight of luggage placed on the seat cushion areborne by the cover member and do not act on the control unit.

Preferably, buckles for fastening seat belts for passenger protectionare disposed behind the cover member, so that the area behind the covermember is used effectively. Also, by buckles being disposed behind thecover member, passengers can be restricted from sitting on the centralpart where the cover member is disposed.

Also, preferably, the cover member has in its front end an openingthrough which passes at least one harness extending from the controlunit. By this means, harnesses can be confined to the front part of thecontrol unit, and the harnesses can be laid outside of the passengersitting positions. Therefore, when passengers sit on the sittingpositions, the weight of the passengers does not act on the harnesses.

Preferably, the electric stowing system of the invention furtherincludes a seat operating switch for stowing in the floor recess theseat made up of the seat back and the seat cushion, and the seatoperating switch is disposed behind the rearmost seat among the seatsand in the proximity of the tailgate opening of the vehicle. In thiscase, when the seat operating switch is operated, because this is donewhen the tailgate is open, the switch can only be operated when thevehicle is stationary. Because the operator watches the movement of theelectric seat from the tailgate while operating it, luggage can beprevented from being sandwiched between the seat and the vehicle bodyand damage to the system can be prevented.

Preferably, the seat operating switch only progresses the seat stowingoperation while its ON state is maintained. In this case, because thestowing operation stops as soon as the operating switch is released, thestowing operation can be carried out without accidents.

Preferably, when the seat has stopped within the range through which theseat swings, a warning is provided for a predetermined time. By thismeans, the operator can be made aware certainly that the seat hasstopped.

Preferably, the stowing system of the invention further includes awarning device for, when the seat cushion is not locked to the floor,warning that it is not locked, and this warning device is provided onthe driver's side. This stops the driver from driving the vehicle whenthe seat cushion is not locked. This warning device is for examplerealized by lighting or flashing an indicator such as a display lampprovided on an instrument panel. By this means, the driver can be madeaware without fail that the seat cushion is not locked.

Preferably, the warning is given when the seat is at a sittable angle tothe floor. This allows a luggage compartment divided into two parts tobe created by bringing the folded seat to the vertical. In this case,because the angle is not one such that a passenger can sit on the seat,a warning is unnecessary.

Preferably, the stowing system of the invention further includes adevice for producing a warning sound when the seat back is tippedforward. In this case, the forwardly tipped state of the seat back canbe made known to passengers with the warning sound. If when the seatcushion is not locked a warning is provided for example by lighting of adisplay lamp as mentioned above, abnormality of the seat back andabnormality of the seat cushion can be distinguished.

Also, in the stowing system of the invention, the swinging means has adrive motor and a warning is provided when the motor current value ofthe drive motor is above a predetermined value. Consequently, it isunnecessary for a current sensor to be disposed in the small seat, andsimplification is possible.

Preferably, a coupling part of the drive motor has a slip clutch. Inthis case, for example when the seat is swinging, when an item ofluggage is sandwiched between the seat and the floor and an excessivecurrent arises in the drive motor, the excessive current through thedrive motor is moderated by the slip clutch and damage is reduced.

Also, in an electric stowing system according to the invention, the seatback forward-tipping means has a reclining mechanism, having a springfor urging the seat back in the forward-tipping direction, which turnsabout a pivot shaft of the seat back, and unlocking means for unlockingthe reclining mechanism. Consequently, when the seat back is to betipped forward, by unlocking the reclining mechanism by operating theunlocking means, the seat back can be swiftly tipped forward underspring force, and the work needed from the passenger is reduced.

The reclining mechanism may have unlocking means for unlocking thereclining mechanism manually. In this case, when the seat back is pulledupright, the reclining mechanism can be unlocked by hand and the seatback set to a desired angle of recline.

Preferably, a one-way damper is provided between the seat cushion andthe seat back so that the damper function acts with respect to theforward tipping direction of the seat back but the damper function doesnot act with respect to the return direction. In this case, when theseat back is tipping forward, by means of the damper effect a smooth andgentle forward tipping action can be realized. When the seat back isbeing returned, the damper function has no effect, and the seat back canbe pulled up smoothly.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic side view showing a vehicle equipped with anelectric vehicle seat stowing system according to the invention;

FIG. 2 is a perspective view illustrating a rearmost rear seat shown inFIG. 1;

FIG. 3 is a perspective view showing an electric vehicle seat stowingsystem according to a first embodiment of the invention; FIG. 4A is asectional view on the line 4-4 in FIG. 2, and FIG. 4B is a sectionalview showing a headrest tipped forward;

FIG. 5 is a view of a seat forward-tipping mechanism made up of areclining mechanism and unlocking means;

FIG. 6 is a perspective view of a damper mechanism shown in FIG. 3; FIG.7 is a perspective view of the unlocking means shown in FIG. 5;

FIG. 8 is an exploded perspective view of the unlocking means shown inFIG. 7;

FIG. 9A and FIG. 9B are views showing a fastener provided on the rearside of a rear seat so that the unlocking mechanism shown in FIG. 7 canbe unlocked manually;

FIG. 10 is a detail view of cushion locking means shown in FIG. 3;

FIG. 11 is a flow chart of stowing a seat in a floor recess;

FIG. 12A and FIG. 12B are views illustrating actions in stowing a seat;

FIG. 13A and FIG. 13B are views showing a locked state and an unlockedstate of a reclining mechanism;

FIG. 14 is a view showing an actuator of unlocking means having operatedin an unlocking direction;

FIG. 15A and FIG. 15B are views showing an unlocked reclining mechanismand unlocking means;

FIG. 16A is a view showing the reclining mechanism locked with the seatback tipped forward, and FIG. 16B is a view showing the seat back tippedforward;

FIG. 17A and FIG. 17B are views showing a ratchet and a latch of cushionlocking means in engaged and disengaged states;

FIG. 18A, FIG. 18B, FIG. 19A and FIG. 19B are views showing cushionlocking means and a striker engaged and disengaged;

FIG. 20A and FIG. 20B are views showing a seat being stowed in a floorrecess and having been completely stowed;

FIG. 21 is a flow chart of returning a seat stowed in a floor recess;

FIG. 22 is a view showing a return switch of a seat operating part beingturned ON;

FIG. 23A and FIG. 23B are a view showing a seat rotated about its pivotshaft in a returning operation and a view showing cushion locking meansengaging with a striker;

FIG. 24A and FIG. 24B are views showing a latch switch of cushionlocking means OFF, and the state of the seat at that time;

FIG. 25A and FIG. 25B are views showing the seat back being returned toits original position;

FIG. 26 is a perspective view of an electric vehicle seat stowing systemaccording to a second embodiment, wherein a control unit is providedwith a cover member;

FIG. 27 is a perspective view showing the rear seat of FIG. 26 with itscover removed;

FIG. 28 is an exploded perspective view showing the cover member andcontrol unit shown in FIG. 27;

FIG. 29 is a sectional view of a seat cushion of the second embodimentshown in FIG. 26;

FIG. 30 is an electrical circuit diagram of an electric stowing systemaccording to the invention;

FIG. 31A, FIG. 31B and FIG. 31C are views showing actions of tippingforward a seat back and stowing a seat in a floor recess;

FIG. 32A and FIG. 32B are views showing actions of returning a seatstowed in a floor recess;

FIG. 33A through FIG. 33D are flow charts showing the operation of acontrol unit in stowing a seat in a floor recess;

FIG. 34A and FIG. 34B are views showing actions of a reclining mechanismof when a seat back is tipped forward;

FIG. 35, FIG. 36A and FIG. 36B are views showing actions of cushionlocking means being unlocked;

FIG. 37 is a view showing the position of a seat cushion when a warningbuzzer buzzes;

FIG. 38A and FIG. 38B are views showing actions of cushion locking meanslocking a seat cushion;

FIG. 39 is a flow chart showing the operation of a control unit when aseat is returned from a stowed state;

FIG. 40 is a flow chart showing the operation of a control unit when aseat is returned after a seat cushion has been rotated to a plannedangle, and is another example of the operation shown in FIG. 39;

FIG. 41A through FIG. 41C are views showing movements of a seat in theoperation shown in FIG. 40;

FIG. 42 is a schematic view showing a vehicle seat stowing system ofrelated art; and

FIG. 43A through FIG. 43C are views showing actions of stowing in afloor recess a seat of a vehicle seat stowing system of related art.

BEST MODE FOR CARRYING OUT THE INVENTION

A vehicle 10 shown in FIG. 1 has, on a floor 12 of a cabin 11, adriver's seat and a passenger seat as front seats 13; a first rear seat14 as a front row behind the front seats 13; a second rear seat (avehicle seat) 15 as a rearmost row behind the first rear seat; and anelectric stowing system 20, according to the present invention, forchanging the attitude of the second rear seat 15 and stowing it in afloor recess 16.

FIG. 2 and FIG. 3 show an electric vehicle seat stowing system 20according to a first embodiment.

The electric vehicle seat stowing system 20 according to a firstembodiment includes the second rear seat 15. The second rear seat 15 hasa seat cushion 21 mounted on a floor 12, seat backs 22, 23 mountedtippably forward and rearward on the left and right on the rear of theseat cushion 21; a left headrest 24 mounted tippably forward andrearward on the top of the left seat back 22, and a right headrest 25mounted tippably forward and rearward on the top of the right seat back23.

A seat operating button 26 is disposed behind the second rear seat 15and in a position away from the side face of the second rear seat 15.

Referring to FIG. 3, the electric vehicle seat stowing system 20includes left and right support shafts 28 a, 28 b respectively attachedto the left and right ends of a cushion frame 27 of the seat cushion 21(see FIG. 2). The right support shaft 28 b is rotatably attached to thevehicle body 17 by a mounting 29. The left support shaft 28 a isattached to swinging means 30. This swinging means 30 is mounted on thevehicle body 17.

The cushion frame 27 has left and right cushion locking means 32, 33 atits front end. A control unit 36 is mounted for example with bolts to acentral part 35 (see FIG. 2), outside of left and right seatingpositions 34, 34 of the cushion frame 27. This control unit 36 forexample has its exterior formed as a rectangular box and is incorporatedinto the seat cushion 21 as shown in FIG. 2.

Although in this first embodiment an example has been described whereinthe control unit 36 is fixed with bolts, the control unit 36 canalternatively be mounted by other means.

Further, in this embodiment, an explanation is made wherein the exteriorof the control unit 36 is a rectangular box, but the form of the controlunit 36 is not limited to it and another form may be applicable.

Because the control unit 36 is incorporated into a central part 35 (seeFIG. 2) of the seat cushion 21 which is outside of the seating positions34, 34, passengers can sit on the seat cushion 21 without sitting on thecontrol unit 36. Therefore, when passengers sit on the second rear seat15, the control unit 36 does not impair the sitting comfort of thepassengers.

A left back frame 41 of the left seat back 22 (see FIG. 2) is attachedby a left reclining mechanism 40 to the left side of the rear end of thecushion frame 27, swingably in the front-rear direction of the vehiclebody, and a right back frame 44 of the right seat back 23 (see FIG. 3)is attached by a right reclining mechanism 43 to the right side of therear end of the cushion frame 27, swingably in the front-rear directionof the vehicle body.

Left unlocking means (unlocking means) 47 for unlocking a left lockmechanism (lock mechanism) 46 of the left reclining mechanism 40 ismounted on the left back frame 41 by a mounting bracket 48. Rightunlocking means (unlocking means) 52 for unlocking a right lockmechanism (lock mechanism) 51 of the right reclining mechanism 43 ismounted on the right back frame 44 by a mounting bracket 53. The seatoperating button 26 is mounted on the vehicle body behind the left seatback.

By transmitting rotation of a drive motor 55 through a speed-reducinggear set 56 to the left support shaft 28 a, for example the swingingmeans 30 rotates the left support shaft 28 a forward by reverse-rotatingthe drive motor 55 and rotates the left support shaft 28 a in reverse byforward-rotating the drive motor 55.

The drive motor 55 and the speed-reducing gear set 56 are mounted to thevehicle body 17 by a bracket 57.

The drive motor 55 is connected to the control unit 36 by a firstharness 58. Because the swinging means 30 is mounted in the vicinity ofthe cushion frame 27, the swinging means 30 can be brought close to thecontrol unit 36 and the length of the first harness 58 can be madeshort.

The left cushion locking means 32 has a cushion lock actuator 60, arelease switch 61 and a latch switch 62, shown in FIG. 10.

The cushion lock actuator 60, the release switch 61 and the latch switch62 are connected to the control unit 36 by a second harness 64.

Because the right cushion locking means 33 has the same construction asthe left cushion locking means 32, a description thereof will beomitted.

The left lock mechanism 46 of the left reclining mechanism 40 has a lockON sensing switch 65, a forward tip sensing switch 66 and a lock OFFsensing switch 67 as shown in FIG. 5.

The lock ON sensing switch 65, the forward tip sensing switch 66 and thelock OFF sensing switch 67 are connected to the control unit 36 by athird harness 68.

Because the right lock mechanism 51 has the same construction as theleft lock mechanism 46, a description thereof will be omitted.

The left unlocking means 47 has an actuator 70 and upper and lower Hallsensors 71, 72 as shown in FIG. 5, FIG. 7 and FIG. 8.

Because the right unlocking means 52 has the same construction as theleft unlocking means 47, a description thereof will be omitted.

The actuator 70 and the upper and lower Hall sensors 71, 72 areconnected to the control unit 36 by a fourth harness 73.

A stowing switch 37 and a return switch 38 operated by the seatoperating button 26 are connected to the control unit 36 by a fifthharness 75. The fifth harness 75 joins the first harness 58 part-wayalong its length.

Because the control unit 36 is incorporated into the central part 35(see FIG. 2), outside of the seating positions 34, 34, of the seatcushion 21 like this, the control unit 36 can be mounted close to theswinging means 30, the left and right cushion locking means 32, 33, theleft and right lock mechanisms 46, 51, and the left and right unlockingmeans 47, 52.

Consequently, the first through fourth harnesses 58, 64, 68 and 73connecting the swinging means 30, the left and right cushion lockingmeans 32, 33, the left and right lock mechanisms 46, 51 the left andright unlocking means 47, 52 and the control unit 36 can be made short.As a result, it is possible to install the first through fourthharnesses 58, 64, 68 and 73 without trouble.

Also, as a result of the control unit 36 being incorporated into theseat cushion 21, the first through fourth harnesses 58, 64, 68 and 73can be incorporated into the seat cushion 21 and the left and right seatbacks 22, 23. Therefore, it is not necessary for the first throughfourth harnesses 58, 64, 68 and 73 to be led from the seat cushion 21and the left and right seat backs 22, 23 to the outside. As a result,when the seat cushion 21 is swung, the first through fourth harnesses58, 64, 68 and 73 are not caught by the seat cushion 21.

The seat operating button 26 has a stowing operation part 26 a and areturning operation part 26 b. Pushing the stowing operation part 26 aturns the stowing switch 370N, and pushing the returning operation part26 b turns the return switch 380N.

FIG. 4A and FIG. 4B show the left headrest 24. The left headrest 24includes a headrest proper 89.

A pair of support members 81, 81 (see also FIG. 3) are disposed with apredetermined spacing in the top part 41 a of the left back frame 41 inthe left seat back 22. The support members 81, 81 have insertion holes82, 82. Insertion rods 83, 83 are inserted into the insertion holes 82,82. A pivot shaft 85 is rotatably attached by brackets (not shown) tobent-over parts 83 a, 83 a of the ends of these insertion rods 83, 83.

A support rod 86 is attached to the pivot shaft 85. A coil spring 87 forswinging the support rod 86 rearward is fitted on the pivot shaft 85.The support rod 86 is held in an in-use position P1 against the springforce of the coil spring 87 by a stopper 88. The stopper 88 is attachedto the bent-over parts 83 a, 83 a. The headrest proper 89 is attached tothe support rod 86.

As shown in FIG. 4B, when a predetermined load is applied to the rearface 24 a of the left headrest 24, the left headrest 24 is foldedagainst the spring force of the coil spring 87 about the pivot shaft 85to a folded position P2, toward the front of the vehicle body.

Here, as the method of folding the left headrest 24, it is conceivableto adopt a construction whereby the left headrest 24 is folded as theleft seat back 22 is tipped forward. However, to make a constructionwhereby the left headrest 24 is folded as the left seat back 22 istipped forward, as members for transmitting the forward tipping movementof the seat back to the headrest, for example members such as aneccentric shaft offset from the pivot shaft 91 of the left seat back 22(see FIG. 2, FIG. 3) and a wire or the like connecting this eccentricshaft to the headrest are necessary, and the construction becomescomplicated. Consequently, the number of parts increases and theassembly labor increases, and it takes time for the left headrest 24 tobe fitted.

With respect to this, the electric vehicle seat stowing system 20 of thepresent invention is constructed so that the rear face 24 a of the leftheadrest 24 is abutted with the rear wall 18 (see FIG. 19A) of the floorrecess 16 and a predetermined load is applied to the rear face 24 a ofthe left headrest 24 to fold the left headrest 24. Therefore, becausemembers such as a shaft offset from the pivot shaft 91 of the left seatback 22 and a wire are unnecessary, it becomes a simple construction.Consequently, by reducing the number of parts and reducing the assemblylabor it is possible to make the fitting time short, and productivitycan be raised.

The forward tipping mechanism of the left headrest 24 shown in FIG. 4Aand FIG. 4B is merely one example, and there is no restriction to this.In short, all that is necessary is that the left headrest 24 beconstructed to be forwardly tippable by a predetermined load beingapplied to the rear face 24 a of the left headrest 24 and that the leftheadrest 24 be constructed to be returnable to its in-use position whenthe load on the rear face 24 a is removed.

Because the right headrest 25 is of the same construction as the leftheadrest 24, a description thereof will be omitted.

FIG. 5 shows a seat back forward tipping mechanism of an electricstowing system for a vehicle seat according to the invention. This seatback forward tipping mechanism has a reclining mechanism 40 andunlocking means 47.

The left reclining mechanism 40 has the lock mechanism 46, the pivotshaft 91, a one-way damper 910, the forward tip sensing switch 66, thelock ON sensing switch 65 and the lock OFF sensing switch 67.

A spiral spring 49 (see FIG. 13B) for urging the seat back 22 to tipforward is provided on the pivot shaft 91.

The left and right one-way dampers 910 shown in FIG. 3 are dampers whosedamper functions work when the seat backs 22, 23 are tipping forward andrealize gentle forward tipping of the seat backs 22, 23, but whosedamper functions do not work when the seat backs 22, 23 are returning toan upright state from their forwardly tipped state.

As these one-way dampers 910, for example the damper disclosed inJP-UM-A-6-80039 is used. This damper is shown in FIG. 6.

Referring to FIG. 6, the one-way damper 910 is made up of a damperhaving a first rotating body 920, a second rotating body 921 consistingof a gear, and a damper member interposed between the first and secondrotating bodies 920, 921; an arm 922 which rotates along with rotationof the second rotating body 921; a friction plate, interposed betweenthe second rotating body 921 and the lower end of the arm 922, fortransmitting rotation of the second rotating body 921 to the arm 922; agear 923 rotatably attached to the upper end of the arm 922 and meshingwith the second rotating body 921; a first stopper 924 having a gearpart; and a second stopper 925.

When the first rotating body 920 rotates in the arrow A direction, thesecond rotating body 921 is also rotated in the arrow A direction by thedamper member, and under the action of the friction plate the arm 922also rotates in the arrow A direction. When this happens, because thegear 923 meshes with the first stopper 924, the rotation of the gear 923is stopped, and the rotation of the second rotating body 921 meshingwith the gear 923 is also stopped. Consequently, a damper function actswith respect to rotation of the first rotating body 920 in the arrow Adirection, and the rotation is made gentle.

When the first rotating body 920 rotates in the arrow B direction, thesecond rotating body 921 and the arm 922 also rotate in the arrow Bdirection, but the rotation of the arm 922 is stopped by the secondstopper 925. Because the gear 923 is free to rotate, the rotation of thesecond rotating body 921 is not stopped. Therefore, no damper functionacts on the first rotating body 920 with respect to the arrow Bdirection.

The left lock mechanism 46 fixes the left seat back 22 in a forwardlytipped position or an upright position. A base 90 is fixed with bolts tothe cushion frame 27. A plate 92 is attached to the base 90 by the pivotshaft 91, swingably in the front-rear direction of the vehicle body.

The base 90 has first and second locking gears 93, 94 at its upper end.A lock gear 95 capable of meshing with the first and second gears 93, 94is formed on a lower swing lever 96. The lower swing lever 96 isswingably attached to the plate 92 by a lower pin 97. An intermediateswing lever 98 for pressing the end of the lower swing lever 96 isswingably attached to the plate 92 by an intermediate pin 99. Theintermediate swing lever 98 has an operating pin 100. This operating pin100 fits in a dogleg-shaped guide hole 101 formed in an upper swinglever 102. The upper swing lever 102 is swingably attached to the plate92 by an upper pin 103.

When the upper swing lever 102 swings about the upper pin 103, theintermediate swing lever 98 is swung about the intermediate pin 99 bythe guide hole 101 and the operating pin 100. A tension spring 104 isfitted between the lower swing lever 96 and the upper swing lever 102.

By the upper swing lever 102 being urged about the upper pin 103 asshown by the arrow [1] under the spring force of the tension spring 104,the operating pin 100 in the guide hole 101 is pressed by the upperswing lever 102 as shown by the arrow [2]. As a result, the end of thelower swing lever 96 is pushed downward by the end of the intermediateswing lever 98, and the lock gear 95 of the lower swing lever 96 iscaused to mesh with the first gear 93. Consequently, the plate 92 isheld in a predetermined position.

The left lock mechanism 46 has the lock OFF sensing switch 67, whichsenses the movement of the upper swing lever 102; the forward tipsensing switch 66, which is operated by a cam 105 provided on the pivotshaft 91; and a lock ON sensing switch 65, which senses the movement ofthe intermediate swing lever 98. The upper swing lever 102 and the leftunlocking means 47 are connected by a connecting cable 110. Also, oneend of an unlocking lever 106 for releasing the locked state of the base90 and the lower swing lever manually is attached to the upper swinglever 102. The unlocking lever 106 is approximately L-shaped and rotatesabout a pin 107 provided on the plate 92.

FIG. 7 and FIG. 8 show the left unlocking means 47 shown in FIG. 5.

The left unlocking means 47 includes the actuator 70 provided on themounting bracket 48 attached to the left back frame 41 (see FIG. 3). Arising/falling shaft 114 projects from the actuator 70, and a magnet 115is attached to the rising/falling shaft 114. An extension part 116 ofthe magnet 115 is fitted in a guide 117. The upper and lower Hallsensors 71, 72 are attached to parts of the mounting bracket 48corresponding to the upper and lower ends of the rising/falling shaft114.

A connecting member 118 bent in a crank shape is attached to the end ofthe rising/falling shaft 114. The connecting member 118 has an engaginggroove 119. A stopper arm 120 provided on the end of an inner cable 111of the connecting cable 110 is fitted in and engaged with the engaginggroove 119.

An anchoring part 121 of an outer cable 121 (see FIG. 8) of theconnecting cable 110 is fitted in an anchoring groove 123 of a supportpart 122 formed on the top of the mounting bracket 48 as shown in FIG.8. The distal end of a lock pin 125 is hooked on a hook piece 126 of themounting bracket 48 and the base ends of the lock pin 125 are engagedwith engaging slots 127, 127, whereby the anchoring part 121 of theconnecting cable 110 is prevented from coming out of the anchoring slot123.

As shown in FIG. 5, by the actuator 70 of the left unlocking means 47being operated or by the unlocking lever 106 being turned manually, therising/falling shaft 114 is lowered, and the upper swing lever 102 islifted upward by the inner cable 111. Consequently, the upper swinglever 102 is turned clockwise against the spring force of the tensionspring 104. As a result, the lock gear 95 of the lower swing lever 96moves away from the first gear 93, and the plate 92 tips forward aboutthe pivot shaft 91. At this time, the urging force of the spiral spring49 (see FIG. 13B) provided on the pivot shaft 91 causes the left seatback 22 to tip forward, but the damper function of the one-way damper910 makes it tip forward gently.

During operation of the left unlocking means 47, for example theactuator 70 may fail. In this case, first, the base ends of the lock pin125 are disengaged from the engaging slots 127, 127 of the mountingbracket 48 and then the distal end of the lock pin 125 is disengagedfrom the hook piece 126 of the mounting bracket 48, and the lock pin 125is thereby removed from the mounting bracket 48. Then, the anchoringpart 121 of the connecting cable 110 is removed from the anchoring slot123 of the support part 122, and the inner cable 111 is removed from theengaging slot 119 of the connecting member 118. As a result, the innercable 111 is disconnected from the actuator 70, and under the springforce of the tension spring 104 shown in FIG. 5 the lock gear 95 of thelower swing lever 96 meshes with the first gear 93 and the second gear94 and fixes the plate 92.

Thus, even if the actuator 70 fails, because the plate 92 can be fixed,the left seat back 22 can be held.

As shown in FIG. 9A, covers 22 a, 23 a covering the rear sides of theleft and right seat backs 22, 23 have slide fasteners 131, 131 inpositions 130, 130 corresponding to the left and right unlocking means47, 52.

The left and right slide fasteners 131, 131 are the same, andhereinafter the left slide fastener 131 will be described, and adescription of the right slide fastener 131 will be omitted.

As shown in FIG. 9B, a seat pad 133 is provided on the inner side of thecover 22 a. This seat pad 133 has an opening 132 for maintenance access.The opening 132 is opened and closed by opening and closing the leftslide fastener 131. Accordingly, opening the left slide fastener 131reveals the access opening 132 and exposes the left unlocking means 47.Closing the slide fastener 131 covers the left unlocking means 47 withthe seat pad 133.

As a result of the left slide fastener 131 and the access opening 132being provided like this, even when the actuator 70 fails, it ispossible to disconnect the inner cable 111 of the connecting cable 110from the actuator 70 easily by opening the left slide fastener 131 andthe access opening 132 and removing the lock pin 125 from the mountingbracket 48. Also, the left slide fastener 131 and the access opening 132can be opened to carry out maintenance of the actuator 70 and so onthrough the access opening 132.

FIG. 10 shows the left cushion locking means 32 shown in FIG. 3.

The left cushion locking means 32 is attached to the cushion frame 27shown in FIG. 3 by a bracket 135. A latch 136 is pivotally attached tothe bracket 135 by a latch pin 137. A ratchet 138 is pivotally attachedto a bracket by a ratchet pin 139, and faces the latch 136 so as toengage and disengage therewith. The cushion lock actuator 60 isconnected to the ratchet 138 by an operating rod 140.

Operation of the cushion lock actuator 60 causes the ratchet 138 toswing as shown by the arrow [3] about the ratchet pin 139 and unlock thelatch 136. Consequently, by the bracket 135 being lifted up togetherwith the seat cushion 21 (see FIG. 2), the latch 136 is turned about thelatch pin 137 and an engaging slot 141 formed in the latch 136 isdisengaged from a striker 142. The striker 142 is a member fixed to thefloor 12 (see FIG. 2, FIG. 3) of the vehicle body 17.

The left cushion locking means 32 has the release switch 61, whichsenses the movement of the ratchet 138; the latch switch 62, whichsenses the movement of the latch 136; and a lock switch 63.

The release switch 61 turns ON when the ratchet 138 has been pulled bythe cushion lock actuator 60 and turns OFF when the ratchet 138 hasreturned.

The latch switch 62 turns ON when the latch 136 has turned and turns OFFwhen the latch 136 has been pushed up by the striker 142.

The lock switch 63 turns OFF when the ratchet 138 has returned to itsinitial position.

Next, the operation of the electric vehicle seat stowing system 20 willbe described, on the basis of FIG. 11 through FIG. 25B. When theoperation of the electric vehicle seat stowing system 20 is implemented,the left and right seat backs 22, 23 and the left and right headrests24, 25 and so on operate in the same way, and here, to facilitateunderstanding, only the left seat back 22 and the left headrest 24 andso on will be discussed, and a description for the right seat back 23and the right headrest 25 will be omitted.

First, stowing operation of an electric stowing system 20 for a vehicleseat according to the invention will be described, on the basis of FIG.11 through FIG. 20B.

FIG. 11 shows a flow chart illustrating the stowing operation of anelectric vehicle seat stowing system (first embodiment) according to theinvention.

Step (hereinafter abbreviated to ST) 01: As shown in FIG. 12A, atailgate 146 is opened, and the seat operating button 26 is pushed toturn the stowing switch 370N.

ST02: The lock mechanisms are unlocked, and the seat backs are tippedforward by spring force.

ST03: After the seat backs are locked in their forwardly tippedpositions, the seat cushion locks are released.

ST04: The seat cushion is swung toward the rear of the vehicle body.

ST05: The second rear seat (the seat cushion and the right and left seatbacks) is stowed in the floor recess.

The contents of ST01 through ST05 will now be explained in detail.

As shown in FIG. 12A, a user 145 opens a tailgate 146 provided at therear of the vehicle body 17 upward. The opening of the tailgate 146turns ON a tailgate OPEN switch (not shown). Then, the stowing operationpart 26 a of the seat operating button 26 provided behind the secondrear seat 15 is pushed with a finger 147 to turn the stowing switch370N.

After the control unit 36 detects that the tailgate OPEN switch is ON,the actuator 70 of the left unlocking means 47 shown in FIG. 12B isoperated. The operation of the actuator 70 moves the rising/fallingshaft 114 downward as shown by the arrow a. By moving downward, therising/falling shaft 114 pulls the inner cable 111 of the connectingcable 110 with the connecting member 118 as shown by the arrow b.

In FIG. 13A, when the inner cable 111 of the connecting cable 110 ispulled as shown by the arrow b, the upper swing lever 102 turnsclockwise about the upper pin 103 as shown by the arrow c. As a result,the operating pin 100 in the guide hole 101 is subjected to a forcewhich moves it to the left in the figure. The intermediate swing lever98 turns counterclockwise about the intermediate pin 99 as shown by thearrow d.

As shown in FIG. 13B, the turning of the intermediate swing lever 98causes the end 98 a of the intermediate swing lever 98 to leave the end96 a of the lower swing lever 96. Then, an intermediate cam face 98 b ofthe intermediate swing lever 98 pushes on a projecting arm 96 b of thelower swing lever 96. As a result of the projecting arm 96 b of thelower swing lever 96 being pushed, the lower swing lever 96 turnscounterclockwise about the lower pin 97 as shown by the arrow e, and thelock gear 95 of the lower swing lever 96 is lifted up.

This unmeshes the lock gear 95 and the first gear 93 and unlocks theleft lock mechanism 46. When the left lock mechanism 46 is unlocked likethis, under the spring force of the spiral spring 49 provided on theleft reclining mechanism 40, the plate 92 tips forward toward the frontof the vehicle body about the pivot shaft 91 as shown by the arrow f. Atthis time, as mentioned above, a damper function of the one-way damper910 shown in FIG. 6 works, and the plate 92 tips forward gently. Then,the lock OFF sensing switch 67 is turned ON by the upper swing lever102.

When the lock OFF sensing switch 67 is turned ON by the upper swinglever 102 as shown in FIG. 13B, an ON signal of the lock OFF sensingswitch 67 is inputted to the control unit 36 (see FIG. 3), and theactuator 70 of the left unlocking means 47 shown in FIG. 14 stops. As aresult, the inner cable 111 of the connecting cable 110 is kept pulleddown.

For example when a problem has arisen in the lock OFF sensing switch 67,when the magnet 115 reaches the lower Hall sensor 72 as shown in FIG.14, the lower Hall sensor 72 senses the magnet 115, and on the basis ofa detection signal from the lower Hall sensor 72 the control unit 36controls the actuator 70 to stop. By this means the rising/falling shaft114 is prevented from descending too far and the actuator 70 isprotected.

As shown in FIG. 15A, when the plate 92 has finished tipping forward,the forward tip sensing switch 66 is pressed by the cam 105 and turnsON. An ON signal from the forward tip sensing switch 66 is inputted tothe control unit 36 (see FIG. 3). The control unit 36 drives theactuator 70 of the left unlocking means 47 shown in FIG. 15B. Therising/falling shaft 114 moves upward as shown by the arrow g.

When the rising/falling shaft 114 has risen to a predetermined positionand the magnet 115 has reached the position of the upper Hall sensor 71,the upper Hall sensor 71 senses the magnet 115. On the basis of adetection signal from the upper Hall sensor 71 the control unit 36 stopsthe actuator 70. This removes the downward tension applied to the innercable 111 of the connecting cable 110.

As a result of the downward tension on the inner cable 111 of theconnecting cable 110 shown in FIG. 15B being removed, the spring forceof the tension spring 104 shown in FIG. 16A causes the upper swing lever102 to turn counterclockwise about the upper pin 103 as shown by thearrow h. Consequently, the operating pin 100 in the guide hole 101 ispressed by the upper swing lever 102 as shown by the arrow i. Thiscauses the intermediate swing lever 98 to turn clockwise about theintermediate pin 99 as shown by the arrow j. The end 98 a of theintermediate swing lever 98 pushes the end 96 a of the lower swing lever96 downward.

The end 96 a of the lower swing lever 96 being pushed downward causesthe lock gear 95 of the lower swing lever 96 to mesh with the first gear93. Consequently, the left lock mechanism 46 becomes locked and theplate 92 is held in its forwardly tipped position.

As shown in FIG. 16B, the left seat back 22 tips forward together withthe plate 92 and moves to a position P1, and the left lock mechanism 46shown in FIG. 16A becomes locked. The left seat back 22 is locked in theforwardly tipped position P1.

In FIG. 16A, as a result of the intermediate swing lever 98 turningabout the intermediate pin 99 as shown by the arrow j, the lock ONsensing switch 65 turns ON.

Referring to FIG. 17A, when the control unit 36 (see FIG. 3) receives anON signal from the lock ON sensing switch 65 shown in FIG. 16A, thecushion lock actuator 60 operates and the operating rod 140 retracts asshown with an arrow. Consequently, the ratchet 138 swings about theratchet pin 139 as shown by the arrow k.

In FIG. 17B, the turning of the ratchet 138 causes its lock part 138 ato disengage from a lock claw 136 a of the latch 136, and the latch 136is unlocked. At the same time, the release switch 61 is turned ON by apin 149.

Referring to FIG. 18A, when the control unit 36 receives an ON signalfrom the release switch 61 shown in FIG. 17B, the control unit 36 stopsthe cushion lock actuator 60 shown in FIG. 17A and drives the drivemotor 55 of the swinging means 30. The drive of the drive motor 55causes the left support shaft 28 a to rotate forward, and with the leftseat back 22 locked in its forwardly tipped position the seat cushion 21is swung toward the rear of the vehicle body together with the left seatback 22 as shown by the arrow m.

In FIG. 18B, the bracket 135 of the left cushion locking means 32 risingas shown by the arrow m integrally with the seat cushion 21 shown inFIG. 18A causes the latch 136 provided on the bracket 135 to rise.

Because the striker 142 is disposed inside the engaging slot 141 of thelatch 136, the latch 136 rising causes a lower side 141 a of theengaging slot 141 to interfere with the striker 142 and the latch 136turns about the latch pin 137 as shown by the arrow n.

In FIG. 19A, the latch switch 62 is turned ON, the striker 142 comes outof the engaging slot 141 of the latch 136, and the left cushion lockingmeans 32 is unlocked.

When the control unit 36 (see FIG. 3) detects that the latch switch 62is ON, the control unit 36 operates the cushion lock actuator 60 to movethe operating rod 140 forward as shown by the arrow p.

The ratchet 138 swings about the ratchet pin 139 as shown by the arrow qand presses a cam face 138 b of the ratchet 138 against a cam face 136 bof the latch 136. Consequently, the latch 136 is held in a position suchthat the striker 142 is out of the engaging slot 141.

In FIG. 19B, as a result of the left cushion locking means 32 beingunlocked, the seat cushion 21 becomes swingable further about the leftsupport shaft 28 a as shown by the arrow m toward the rear of thevehicle body. At this time, the control unit 36 detects the motorcurrent of the drive motor 55 and determines whether or not the detectedvalue is above a threshold value.

For example, when the seat cushion 21 interferes with an obstruction(not shown) and the motor current exceeds the threshold value, the drivemotor 55 is stopped.

When the seat cushion 21 does not interfere with an obstruction, becausethe motor current value does not rise above the threshold value, theseat cushion 21 swings further toward the rear of the vehicle body asshown by the arrow m.

Here, as a result of the control unit 36 being incorporated into theseat cushion 21, the first through fourth harnesses 58, 64, 68 and 73(see FIG. 3) can be incorporated into the seat cushion 21 and the seatbacks 22, 23. Consequently, when the seat cushion 21 is made to swing,the first through fourth harnesses 58, 64, 68 and 73 are not caught bythe seat cushion 21.

Next, on the basis of FIG. 20A and FIG. 20B, the operation of ST05 shownin FIG. 11 will be explained.

As shown in FIG. 20A, when the seat cushion 21 swings toward the rear ofthe vehicle body and stows in the floor recess 16, the rear face 24 a ofthe left headrest 24 abuts with the upper end 18 a of the rear wall 18of the floor recess 16. Because a predetermined load F acts on the rearface 24 a of the left headrest 24, the left headrest 24 is folded aboutthe pivot shaft 85 as shown by the arrow r against the spring force ofthe coil spring 87 (see FIG. 4). In this state, the seat cushion 21swings toward the rear of the vehicle body as shown by the arrow m.

As shown in FIG. 20B, the seat cushion 21 abuts with the bottom face 19of the floor recess 16. The motor current value of the drive motor 55(see FIG. 3) rises above the threshold value and the drive motor 55stops. As a result, the seat cushion 21 and the left seat back 22 (thesecond rear seat 15) are stowed in the floor recess 16 and the stowingprocess ends.

In stowing the seat cushion 21 and the left seat back 22 (the secondrear seat 15) in the floor recess 16 like this, because it is notnecessary for the left headrest 24 to be removed from the left seat back22, the second rear seat 15 can be stowed in the floor recess 16 easily,without trouble.

Also, as shown in FIG. 20A, by the rear face 24 a of the left headrest24 abutting with the upper end 18 a of the rear wall 18 forming thefloor recess 16, the left headrest 24 swings about the pivot shaft 85 asshown by the arrow r and is folded against the spring force of the coilspring 87 (see FIG. 4). Because consequently members such as a shaftoffset from the pivot shaft 91 (see FIG. 3) of the left seat back 22 anda wire can be made unnecessary, the construction can be made simple.

Next, the returning operation of the electric vehicle seat stowingsystem 20 will be described, on the basis of FIG. 21 through FIG. 25B.

FIG. 21 is a flow chart illustrating the returning operation of thesecond rear seat 15.

ST10: The tailgate is opened, and the seat operating button is pushed toturn the return switch ON.

ST11: The seat cushion is swung forward in the vehicle body.

ST12: The seat cushion is locked in its returned position.

ST13: The seat back is pulled upright by hand.

The contents of ST10 through ST13 will now be described in detail, onthe basis of FIG. 22 through FIG. 25B.

FIG. 22 is an illustration of ST10 of FIG. 21.

The user 145 opens the tailgate 146 at the back of the vehicle body 17upward. Opening the tailgate 146 turns the tailgate OPEN switch (notshown) ON. After that, the returning operation part 26 b of the seatoperating button 26 mounted behind the second rear seat 15 is pressedwith a finger 147 to turn ON the return switch 38.

After receiving the ON signal from the tailgate OPEN switch, the controlunit 36 drives the drive motor 55 (see FIG. 2, FIG. 3) of the swingingmeans 30. The drive of the drive motor 55 swings the seat cushion 21about the left support shaft 28 a integrally with the left seat back 22as shown by the arrow s and so takes it out from inside the floor recess16.

As the seat cushion 21 and the left seat back 22 are taken outintegrally from the floor recess 16, the left headrest 24 ceases to makecontact with the rear wall 18 of the floor recess 16 and is returned toits ready position (see FIG. 23A) by the spring force of the coil spring87. Therefore, in the taking out of the seat cushion 21 and the leftseat back 22 (the second rear seat 15) from inside the floor recess 16,the trouble of returning the left headrest 24 to its ready position byhand can be eliminated.

Then, as shown in FIG. 23A, as a result of the seat cushion 21 swingingas shown by the arrow s toward the front of the vehicle body, the rearside of the seat cushion 21 comes close to the floor 12.

Here, because the control unit 36 is incorporated into the seat cushion21, the first through fourth harnesses 58, 64, 68 and 73 (see FIG. 3)are incorporated into the seat cushion 21 and the left and right seatbacks 22, 23. Consequently, when the seat cushion 21 is swung, the firstthrough fourth harnesses 58, 64, 68 and 73 are not caught by the seatcushion 21.

As shown in FIG. 23B, the upper side 141 b of the engaging slot 141 ofthe latch 136 abuts with the striker 142. In this state, the bracket 135and the latch 136 of the left cushion locking means 32 descendintegrally with the seat cushion 21 (see FIG. 23A) as shown by the arrows, the upper side 141 b of the engaging slot 141 pushes the striker 142,and the latch 136 turns about the latch pin 137 as shown by the arrow t.

As shown in FIG. 24A, the latch 136 returns to its locked position, andthe latch switch 62 turns OFF. The control unit 36 shown in FIG. 24Breceives an OFF signal from the latch switch 62 and stops the drivemotor 55 (see FIG. 2, FIG. 3) of the swinging means 30. Also, when thecontrol unit 36 receives the OFF signal from the latch switch 62, itdrives the actuator 70 of the left unlocking means 47 (see FIG. 5). Asexplained with reference to FIG. 12B through FIG. 13B, the driving ofthe actuator 70 unlocks the left lock mechanism 46 (see FIG. 5).

Then, as shown in FIG. 24B, the seat cushion 21 is locked in its readyposition by the left cushion locking means 32.

FIG. 25A and FIG. 25B show the seat back 22 being pulled upright by handas described in ST13 of FIG. 21.

As shown in FIG. 25A, the user 145 places a hand 148 on the left seatback 22 and swings the left seat back 22 about the pivot shaft 91 towardthe rear of the vehicle body as shown by the arrow u against the springforce of a torsion spring (not shown).

As shown in FIG. 25B, when the left seat back 22 has been swung to thedesired position, the finger 147 is removed from the returning operationpart 26 b of the seat operating button 26. When the return switch 38turns OFF, the control unit 36 drives the actuator 70 of the leftunlocking means 47 (see FIG. 5).

In the same way as described with reference to FIG. 15A through FIG.16A, the driving of the actuator 70 returns the left lock mechanism 46(see FIG. 5) to its locked state. As a result, the left seat back 22 isheld in the desired position, and the return operation of the secondseat 15 is ended.

Thus, with the electric vehicle seat stowing system 20, the second rearseat 15 can be stowed in the floor recess 16 and can be returned fromthe floor recess 16 to its ready position by electric power.

Here, in FIG. 1, when the second rear seat 15 is being taken out of thefloor recess 16, it is conceivable for example that the left seat back22 might be lifted upright without the seat cushion 21 being locked bythe left cushion locking means 32. At this time, the latch switch 62shown in FIG. 24A is being kept ON.

In this state, when the ignition switch (not shown) of the vehicle 10 isturned ON, the control unit 36 receives an ON signal from the latchswitch 62 and for example lights a warning lamp 152 provided in aninstrument cluster 151 on an instrument panel 150. Thus the driver canbe made aware that the seat cushion 21 has not been locked by the leftcushion locking means 32.

Next, on the basis of FIG. 26 through FIG. 29, an electric vehicle seatstowing system 160 according to a second embodiment will be described.In the electric vehicle seat stowing system 160 of this secondembodiment, parts the same as parts in the electric vehicle seat stowingsystem 20 of the first embodiment have been given the same referencenumerals and will not be described again.

Referring to FIG. 26, the electric vehicle seat stowing system 160 ofthe second embodiment has a second rear seat 15. The second rear seat 15has a seat cushion 21 mounted on a floor 12; left and right seat backs22, 23 mounted tippably forward and rearward on the rear of the seatcushion 21; a left headrest 24 mounted tippably forward and rearward onthe top of the left seat back 22; and a right headrest 25 mountedtippably forward and rearward on the top of the right seat back 23.

A left side seat belt (seat belt) 162 is installed in a second rear seat15 left side vehicle body panel (not shown). A left tongue 164 ismovably fitted to a webbing 163 of the left side seat belt 162.

A left buckle 165 for clasping this left tongue 164 is connected by abelt 166 to a rear pipe 27 b (see FIG. 29) of a cushion frame 27. Thisleft buckle 165 is disposed in a roughly central rear recess 168 of theseat cushion 21.

Also, a right side seat belt (seat belt) 172 is installed in a secondrear seat 15 right side vehicle body panel (not shown). A right tongue174 is movably fitted to a webbing 173 of this right side seat belt 172.

A right buckle 175 for clasping this right tongue 174 is connected by abelt 176 to the rear pipe 27 b (see FIG. 29) of the cushion frame 27.This right buckle 175 is disposed in the roughly central rear recess 168of the seat cushion 21.

A seat operating button 26 is provided in a position behind the secondrear seat 15 and away from the left side face of the second rear seat15. The seat operating button 26 is mounted on a wall face of a vehiclebody panel (not shown).

FIG. 27 shows an electric vehicle seat stowing system according to thesecond embodiment.

Left and right support shafts 28 a, 28 b are attached to the left andright rear ends of the cushion frame 27 of the seat cushion 21 (see FIG.26). The right support shaft 28 b is rotatably mounted to the vehiclebody 17 by a mounting 29. The left support shaft 28 a is attached toswinging means 30. This swinging means 30 is mounted on the vehicle body17.

Left and right cushion locking means 32, 33 are mounted on the left andright front ends of the cushion frame 27. A control unit 181 is disposedon a central part 35 (see FIG. 26) of the cushion frame 27, outside ofleft and right seating positions 34, 34.

Specifically, as shown in FIG. 28, three leg parts 182 extendinghorizontally from the control unit 181 are attached to the upper facecenter 27 a of the cushion frame 27 by connecting members such as bolts183 and nuts 184.

The upper face 181 a of the control unit 181 is covered on its upperside by a dome-shaped cover member 185, whereby the control unit 181 isprotected. This dome-shaped cover member 185 is incorporated into thecentral part 35 (see FIG. 26) of the seat cushion 21. The cover member185 is also fixed with the bolts 183 and nuts 184.

Because the control unit 181 is incorporated into the central part 35(see FIG. 26), outside of the left and right seating positions 34, 34,of the seat cushion 21, passengers can sit on parts of the seat cushion21 which are away from the control unit 181 (that is, the left and rightseating positions 34, 34). As a result, when passengers sit on thesecond rear seat 15, the control unit 181 does not impair the seatingcomfort of the passengers.

A left back frame 41 of the left seat back 22 (see FIG. 26) is mountedby a left reclining mechanism 40 to the left side of the rear of thecushion frame 27, swingably in the front-rear direction of the vehiclebody. A right back frame 44 of the right seat back 23 (see FIG. 2) ismounted by a right reclining mechanism 43 to the right side of the rearof the cushion frame 27, swingably in the front-rear direction of thevehicle body.

A left unlocking mechanism 47 for unlocking a left lock mechanism 46 ofthe left reclining mechanism 40 is mounted on the left back frame 41 bya mounting bracket 48.

A right unlocking mechanism 52 for unlocking a right lock mechanism 51of the right reclining mechanism 43 is mounted on the right back frame44 by a mounting bracket 53.

The seat operating button 26 is mounted on a wall face of a vehicle bodypanel (not shown) behind and to the left of the left seat back 22 (seeFIG. 26).

By transmitting rotation of a drive motor 55 through a speed-reducinggear set-56 (see also FIG. 3) to the left support shaft 28 a, forexample the swinging means 30 rotates the left support shaft 28 aforward by reverse-rotating the drive motor 55 and rotates the leftsupport shaft 28 a in reverse by forward-rotating the drive motor 55.The drive motor 55 and the speed-reducing gear set 56 are mounted to thevehicle body 17 by a bracket 57. The drive motor 55 is connected to thecontrol unit 181 by a first harness 187.

The left cushion locking means 32 has a cushion lock actuator 60, arelease switch 61, a latch switch 62 and a lock switch 63, shown in FIG.10. The cushion lock actuator 60, the release switch 61, the latchswitch 62 and the lock switch 63 are connected to the control unit 181by a second harness 188.

The left lock mechanism 46 of the left reclining mechanism 40 includes alock ON sensing switch 65, a forward tip sensing switch 66 and a lockOFF sensing switch 67, shown in FIG. 5. The lock ON sensing switch 65,the forward tip sensing switch 66 and the lock OFF sensing switch 67 areconnected to the control unit 181 by a third harness 189.

The left unlocking mechanism 47 includes an actuator 70 and upper andlower Hall sensors 71, 72, as shown in FIG. 5, FIG. 7 and FIG. 8. Theactuator 70 and the upper and lower Hall sensors 71, 72 are connected tothe control unit 181 by a fourth harness 191.

A stowing switch 37 and a return switch 38 operated by the seatoperating button 26 are connected to the control unit 181 by a fifthharness 192. The fifth harness 192 is connected to the control unit 181along with the first harness 187, which it joins part-way along itslength.

The seat operating button 26 has a stowing operation part 26 a and areturning operation part 26 b. Pushing the stowing operation part 26 aturns the stowing switch 370N. Pushing the returning operation part 26 bturns the return switch 380N.

The first through fifth harnesses 187, 188, 189, 191, 192 are connectedto the control unit 181 via an opening 193 (see FIG. 28) provided in thefront end 185 a of the cover member 185.

FIG. 28 shows the relationship between the control unit 181 and thecover member 185 shown in FIG. 27.

The control unit 181 for example has its exterior shaped like arectangular box. Three connection parts 195 for connecting threeconnectors 194 to are provided on the front wall 181 b of the controlunit 181. Insertion parts 196 are provided on the left and right sidewalls 181 c, 181 d and the rear wall 181 e of the control unit 181 (onlythe insertion part 196 on the left side part 181 c is shown in thefigure).

By base end parts 182 a (that is, parts bent to the vertical) of thethree leg parts 182 mentioned above being inserted into these insertionparts 196, the leg parts 182 are attached to the left and right sidewalls 181 c, 181 d and the rear wall 181 e.

Each of the leg parts 182 has a mounting hole 182 c formed in its distalend 182 b. The bolts 183 are passed through the mounting holes 182 c andthe bolts 183 are made to project from the mounting holes 182 c.

The projecting bolts 183 are passed through mounting holes 197 formed inthe cover member 185, and the nuts 184 are screwed onto the bolts 183projecting from the mounting holes 197. By this means, the control unit181 and the cover member 185 are mounted to the upper face center 27 aof the cushion frame 27, and the upper face 181 a of the control unit181 is covered with the cover member 185.

The cover member 185 has a cover part 201 formed in its middle andprotruding upward. The opening 193 is formed in the front end of thecover part 201, that is, in the front end 185 a of the cover member 185.The cover member 185 has a mounting plate 202 formed along the lowerends of left and right side walls 201 a, 201 b and the lower end of arear wall 201 c of the cover part 201.

The height H1 of the left and right side walls 201 a, 201 b and the rearwall 201 c of the cover part 201 is set to be slightly greater than theheight H2 of the control unit 181. By this means, the control unit 181can be covered with the cover part 201.

Also, for example the width W1 of the opening 193 of the cover part 201is set to be slightly greater than the width W2 at an intermediateposition of the harnesses 198 extending from the three connectors 194.As a result, the three harnesses 198 extending from the three connectors194 can pass through the opening 193.

FIG. 29 is a sectional view of the seat cushion 21 shown in FIG. 26.

The upper face 181 a of the control unit 181 and the harnesses 198 inpart are surrounded by the dome-shaped cover member 185, and this covermember 185 is incorporated into the central part 35 (see also FIG. 26)of the seat cushion 21.

As a result of the upper face 181 a of the control unit 181 beingsurrounded by the cover member 185, outside loads such as the weight ofthe passengers when passengers are sitting on the seat cushion 21 andthe weight of the luggage when luggage is placed on the seat cushion 21can be borne by the cover member 185. By this means it is possible toprevent the weight of passengers or the weight of luggage from acting onthe control unit 181, and the control unit 181 can be protected fromoutside loads.

Also, as a result of the cover member 185 being incorporated into theseat cushion 21, even when a passenger sits on the seat cushion 21, thecover member 185 does not impair the sitting comfort of the passenger.

Although as explained above the cover member 185 is constructed towithstand outside loads such as the weight of passengers and luggage, itis preferable for passengers not to be seated above the cover member185.

By the opening 193 being formed in the front end 185 a of the covermember 185, the multiple harnesses 198 (see FIG. 28) for connection tothe control unit 181 can be brought together at the front wall 181 b ofthe control unit 181. Consequently, it is not necessary for any harnessto extend toward the rear of the vehicle body through the rear wall 181e of the control unit 181.

As a result, space for forming the central rear recess 168 (see alsoFIG. 26) behind the dome-shaped cover member 185 can be secured, and theleft and right seat belt buckles 165, 175 (see FIG. 26) can be stowed inthis central rear recess 168.

By the left and right seat belt buckles 165, 175 being stowed in thecentral rear recess 168 behind the dome-shaped cover member 185 likethis, the area behind the cover member 185 can be used effectively.

Also, by the left and right buckles 165, 175 being stowed in the centralrear recess 168 behind the cover member 185, passengers can be preventedfrom sitting on the central part 35 containing the dome-shaped covermember 185. By this means it is possible to surely prevent the covermember 185 from deforming under an outside load such as the weight ofpassengers, and the control unit 181 can be surely protected fromoutside loads.

Here, if the multiple harnesses 198 (see FIG. 28) for connection to thecontrol unit 181 were to be connected for example to the left and rightside walls 181 c, 181 d of the control unit 181, the harnesses 198 wouldbe laid underneath the left and right seating positions 34, 34 (see FIG.26).

However, by the harnesses 198 being brought together at the front wall181 b of the control unit 181, the multiple harnesses 198 can be laidaway from the left and right seating positions 34, 34 (see FIG. 26).Consequently, the load of the passengers can be prevented from acting onthe harnesses 198 when passengers sit in the left and right seatingpositions 34, 34.

Although in the first and second embodiments examples were describedwherein an electric vehicle seat stowing system 20 was applied to asecond rear seat 15 of a vehicle capable of carrying 6 to 7 people,there is no restriction to this, and it can also be applied to a rearseat of a vehicle capable of carrying 4 to 5 people.

Also, although in the first and second embodiments examples weredescribed wherein the left and right unlocking means 47, 52 wereincorporated respectively into the left and right seat backs 22, 23,there is no restriction to this, and the left and right unlocking means47, 52 can alternatively be incorporated into the seat cushion 21. Inthis case, fasteners 131, 131 are provided in the parts of the seatcushion 21 corresponding to the left and right unlocking means 47, 52,and access holes 132, 132 are provided on the inner sides of thefasteners 131, 131. Consequently, the connecting cable 110 can be easilydisconnected from the actuator 70 by opening the fasteners 131, 131 andthe access holes 132, 132.

Also, although in the first embodiment an example was described whereinthe fasteners 131, 131 and the access holes 132, 132 were provided inthe rear sides of the left and right seat backs 22, 23, there is norestriction to this, and they may alternatively be provided in otherplaces such as in the front sides or the side faces of the left andright seat backs 22, 23.

Also, although in the second embodiment an example was describedwherein, as the cover member 185, as shown in FIG. 28, a cover part 201is formed centrally, an opening 193 is formed in the front end of thecover part 201, and a mounting plate 202 is formed along the lower endsof left and right side walls 201 a, 201 b and the lower end of a rearwall 201 c of the cover part 201, the shape of the cover member 185 isnot restricted to this. In short, any construction with which the top ofthe control unit 181 can be covered and the multiple harnesses 198 canbe taken out from the control unit 181 to the front can be used.

Next, the operation of the control unit 36, 181 will be described, onthe basis of FIG. 30 through FIG. 41.

FIG. 30 shows an electrical circuit diagram of an electric vehicle seatstowing system.

Referring to FIG. 30, a battery 370 is connected to a control unit 36 byfuses 371, 372 and 373 and an ignition switch 374 and a fuse 375.

A warning lamp 376, an AT shift position switch 377, a tailgate switch378 and a seat operating button 26, which is command means for startingseat operation, are connected to the control unit 36.

Left and right forward tip sensing switches 66R, 66L, a right lock ONsensing switch 65R, a right lock OFF sensing switch 67R, a left lock ONsensing switch 65L, a left lock OFF sensing switch 67L, a right latchswitch 62R, a right release switch 61R, a right lock switch 63R, a leftlatch switch 62L, a left release switch 61L, a left lock switch 63L, anda seat floating sensing switch 380 are connected to the control unit 36.

A short coupler 381 and a ground line 382 are connected to the controlunit 36.

Through an output interface, the drive motor 55 of the swinging means30, the left and right unlocking means 47, 52, a left actuator 70L and aright actuator 70R, a right cushion lock actuator 60R and a left cushionlock actuator 60L are connected to the control unit 36.

As shown in FIG. 3, when the stowing operation part 26 a of the seatoperating button 26 is operated and the stowing switch 37 is therebyturned ON, a seat stowing operation starts, and when the returningoperation part 26 b is operated and the return switch 38 is therebyturned ON a seat returning operation starts.

A motor current detector 383 for detecting the motor current of thedrive motor 55 of the swinging means 30 and a seat cushion positionsensor 384 for detecting the angle of the seat cushion 21 from the floor12 are connected to the control unit 36.

Also, a warning buzzer 385 and a warning 386 are connected to thecontrol unit 36. The warning 386 includes an indicator such as a displaylamp 152 provided in the instrument duster 151 of the instrument panel150 shown in FIG. 1, and for example makes the display lamp 152 flash.The seat operating button 26 is disposed behind the seat.

As shown in FIG. 3, for example a slip dutch 55 b is provided in acoupling part 55 a coupling the drive motor 55 and the speed-reducinggear set 56 of the swinging means 30, so that the mechanism can beoperated manually without the involvement of the control unit 36.

Using these switches and sensors, the control unit 36 operates inaccordance with the flow chart shown in FIG. 33A through FIG. 33D andFIG. 39.

FIG. 31A, FIG. 31B and FIG. 31C show the basic operation of stowing arear seat, and FIG. 32A and FIG. 32B show the basic operation ofreturning a stowed rear seat.

In the rear seat stowing operation, first, as shown in FIG. 31A thetailgate 146 is opened, and the user 145 tips the seat back 22 forwardas shown in FIG. 31B by continuously pushing the stowing operation part26 a of the seat operating button 26.

After that, the forwardly tipped left seat back 22 and the seat cushion21 are rotated together as shown in FIG. 31C and stowed in the floorrecess 16, which is a stowing space. This series of operations iscarried out by electric power.

Next, the operation of returning a seat stowed in the floor recess 16will be described, on the basis of FIG. 32A and FIG. 32B.

First, as shown in FIG. 32A the tailgate 146 is opened, and the user 145pushes the returning operation part 26 b of the seat operating switch 26continuously. From the stowed state wherein the left seat back 22 andthe seat cushion 21 are stowed in the floor recess 16, which is astowing space, the left seat back 22 and the seat cushion 21 rotatetogether and come out of the floor recess 16, and as shown in FIG. 32Bthe forwardly tipped left seat back 22 and seat cushion 21 return totheir predetermined position on the floor 12. This series of operationsis carried out under electrical power. After that, the left seat back 22is returned by hand.

When during the operation of rotating the seat the user releases theswitch, at that moment the rotating operation stops. Also, when anexcessive load arises on the seat during the seat rotation operation, atthat moment the rotating operation stops. When the excessive load isremoved and the switch is operated again, the rotating operationresumes. When the seat rotation operation has stopped like this, by thebuzzer and by the display lamp 152 on the instrument panel 150 beinglit, the user is warned that the cushion is not locked.

Next, the operation of the control unit 36 when the rear seat 15 isstowed in the floor recess 16 will be described, on the basis of theflow chart shown in FIG. 33A through FIG. 33D. The program starts whenthe stowing operation part 26 a of the seat operating button 26 shown inFIG. 3 is pushed with a finger to turn the stowing switch 370N.

ST110: First, it is determined whether or not the shift position of theAT is the Park position. When the shift position is not the Parkposition, execution of the program is ended. When the shift position isthe Park position, processing proceeds to ST111.

ST111: It is determined whether or not the parking brake has beenoperated. When the parking brake has not been operated, execution of theprogram is ended. When the parking brake has been operated, processingproceeds to ST112.

ST112: The output from the tailgate sensor 378 is detected.

ST113: It is determined whether or not the tailgate 146 is open. Whenthe tailgate 146 is not open, execution of the program is ended. Whenthe tailgate 146 is open, processing proceeds to ST114.

ST114: The actuator 70 of the unlocking means 47 is controlled tooperate in its cable-pulling direction. This operation of the actuator70 pulls the connecting cable 110. FIG. 34A shows the recliningmechanism 40 at this time, wherein one end of the upper swing lever 102is pulled and the upper swing lever 102 pivots clockwise about the upperpin 103 as shown with an arrow. This pivoting of the upper swing lever102 causes the lower swing lever 96 and the base 90 to unmesh and thelock mechanism 46 becomes unlocked. The reaction force of the spiralspring 49 (see FIG. 13B) causes the seat back 22 to tip forward in theforward direction of the vehicle body as shown in FIG. 34B.

ST115: It is determined whether or not the lock OFF sensing switch 67has turned ON.

ST116: When the lock OFF sensing switch 67 turns ON, because the leftlock mechanism 46 of the left reclining mechanism 40 is locked, theoperation of the actuator 70 of the left unlocking means 47 is stopped.

ST117: It is determined whether or not the forward tip sensing switch 66is ON.

ST118: The actuator 70 is operated in its cable-returning direction.

ST119: It is determined whether or not the upper Hall sensor 71 hasturned ON.

ST120: When the upper Hall sensor 71 turns ON, the operation of theactuator 70 is stopped.

ST121: It is determined whether or not the lock ON sensing switch 65 hasturned ON. If the lock ON sensing switch 65 turns ON, the seat back 22completes tipping forward and becomes locked.

Next, the operation of rotating the seat back 22 and stowing it in thefloor recess 16 will be described, on the basis of the flow chart ofFIG. 33C and FIG. 33D, and FIG. 35, FIG. 36A and FIG. 36B.

First, a cushion unlocking operation is carried out, in accordance withthe flow chart shown in FIG. 33C.

ST122: As described above, when it is detected that the lock ON sensingswitch 65 is ON, as shown in FIG. 35 the cushion lock actuator 60 isoperated to pull the operating rod 140 in the direction shown with anarrow. This operation of the cushion lock actuator 60 causes the ratchet138 to pivot clockwise about the ratchet pin 139 as shown in FIG. 36A.

ST123: It is determined whether or not the release switch 61 has turnedON.

ST124: When the release switch 61 has turned ON, the operation of thecushion lock actuator 60 shown in FIG. 35 is stopped.

ST125: After the operation of the cushion lock actuator 60 is stopped,the drive motor 55 of the swinging means 30 shown in FIG. 3 starts. Thedrive of the drive motor 55 pivots the rear seat 15 in the direction inwhich it is stowed in the floor recess 16. Then, the latch 136 pivots asshown in FIG. 36B and disengages from the mounting bracket 53.

ST126: It is determined whether or not the latch switch 62 has turnedON.

ST127: When the latch switch 62 turns ON, the cushion lock actuator 60operates to advance the operating rod 140. This advancing of theoperating rod 140 turns the latch 136 counterclockwise about the ratchetpin 139 and returns it to its original state.

ST128: When the drive motor 55 is operating, it is determined whether ornot the motor current value detected by the motor current detector 383shown in FIG. 30 is above a predetermined value.

ST129: When the motor current value is above the predetermined value,driving of the drive motor 55 is stopped. When the motor current valueis smaller than the predetermined value, the drive motor 55 goes onbeing driven.

ST130: When the drive motor 55 stops, the output of the seat cushionposition sensor 384 shown in FIG. 30 is detected.

ST131: It is determined whether or not the value detected by the seatcushion position sensor 384 is below a predetermined value (for example30°) as shown in FIG. 37. When it is greater than the predeterminedvalue, processing ends, and when it is smaller processing proceeds toST132.

ST132: When the value detected by the seat cushion position sensor 384is below the predetermined value, the warning buzzer 385 shown in FIG.30 is sounded. For example the warning buzzer buzzes ten timesintermittently.

Thus, in ST125, when the rear seat 15 rotates to its stowing positionand stops, in ST128 the motor current detector 383 detects the motorcurrent value, and when the motor current value is above a predeterminedvalue due to motor load increase, in ST129 the rotating of the rear seat15 is stopped. This completes the stowing of the rear seat 15 in thefloor recess 16. The operation described above is executed only when thestowing switch 37 of the seat operating button 26 shown in FIG. 3 is ON,and when the seat operating switch 26 is turned OFF, execution is ended.

When the ignition switch 374 in FIG. 30 turns ON, the control unit 36operates and receives an output from the seat cushion position sensor384. Also, the control unit 36 receives an ON/OFF signal from the lockswitch 63. If it is a predetermined value (for example less than 300) ofthe kind shown in FIG. 37, that is, if the lock switch 63 is not ON,this is displayed on the display lamp 152 of the warning 386. By thismeans it is possible to avoid users sitting and traveling when the seatcushion 21 is not surely locked.

Next, the operation of the rear seat 15 moving from being stowed in thefloor recess 16 to being tipped forward will be described, on the basisof the flow chart shown in FIG. 39 and of FIG. 38A and FIG. 38B.

ST340: It is determined whether or not the returning operation button(return switch) 26 b of the seat operating button 26 is being pressed.

ST341: If the return switch 26 b is ON, it is determined whether or notthe shift position is the Park position. When the shift position is notthe Park position, processing ends. When the shift position is the Parkposition, processing proceeds to ST342.

ST342: It is determined whether or not the parking brake is ON. When theparking brake is OFF, processing ends. When the parking brake is ON,processing proceeds to ST343.

ST343: The output from the tailgate sensor 378 shown in FIG. 30 isdetected.

ST344: On the basis of the signal outputted from the tailgate sensor378, it is determined whether or not the tailgate 146 shown in FIG. 1 isopen. When the tailgate 146 is not open, processing ends. When thetailgate 146 is open, processing proceeds to ST345.

ST345: The drive motor 55 shown in FIG. 3 is driven to rotate in thereturn direction.

ST346: When the drive motor 55 has rotated in the seat return direction,it is determined whether or not the motor current value flowing throughthe drive motor 55 is above a predetermined value. When the motorcurrent is below the predetermined value, processing proceeds to ST347and the drive motor 55 continues to operate. When the motor currentvalue is above the predetermined value, processing proceeds to ST348.

ST348: A stop signal is outputted to the drive motor 55, and the drivemotor 55 stops.

ST349: A signal from the seat cushion position sensor 384 is received.

ST350: It is determined whether or not the detected value detected bythe seat cushion position sensor 384 is below a predetermined value ofthe kind shown in FIG. 37 (for example 30°). When it is below thepredetermined value, processing proceeds to ST351, and when it is abovethe predetermined value processing ends.

ST351: A signal is sent to the display lamp 152 warning 386 shown inFIG. 1, the display lamp 152 shown in FIG. 1 is lit or made to flash,and processing ends.

ST352: It is determined whether or not the latch switch 62 shown in FIG.38A and FIG. 38B is OFF. That is, when the cushion locking means 32shown in FIG. 38A descends as shown with an arrow, the latch 136 hitsthe striker 142 and as shown in FIG. 38B turns counterclockwise aboutthe latch pin 137 as shown with an arrow. The latch 136 then abuts withthe latch switch 62 and turns the latch switch 62 OFF.

ST353: It is determined whether or not the lock switch 63 is OFF. As theratchet 138 returns as shown in FIG. 38B, the lock switch 63 turns OFF.

ST354: As a result of the lock switch 63 turning OFF, the rotationaldrive of the drive motor 55 is stopped. This stopping of the drive ofthe drive motor 55 results in the seat back 22 being in a forwardlytipped state with respect to the seat back 22, and the user pulls theleft seat back 22 upright by hand.

As shown in FIG. 34B, with the seat back 22 tipped forward, theunlocking lever 106 is pivoted clockwise about the pin 107 as shown withan arrow. When this happens, one end of the upper swing lever 102 ispulled, and the upper swing lever 102 pivots clockwise about the upperpin 103. As a result of this pivoting of the upper swing lever 102, theintermediate swing lever 98 pivots counterclockwise about theintermediate pin 99, the lower swing lever 96 and the base 90 unmesh,and the lock mechanism 46 is unlocked.

After this left lock mechanism 46 is unlocked, the forwardly tipped seatback 22 is pulled upright by hand. When the left seat back 22 hasreached the desired angle, the unlocking lever 106 is returned. Againthe lock mechanism 46 becomes locked, and the left seat back 22 can beset at a desired angle of inclination.

After processing goes through ST351 and ends, when the ignition switch374 turns ON, on the basis of a detection signal from the seat cushionposition sensor 384 and an OFF signal from the lock switch 63, thecontrol unit 36, if the angle of inclination of the seat cushion 21 is apredetermined value (for example below 30°) of the kind shown in FIG.37, lights the display lamp 152 of the warning 386. Thus it is possibleto avoid users sitting and traveling when the seat cushion 21 is notsurely locked.

Also, when the ignition switch 374 has been turned ON, when it isdetected by the forward tip sensing switch 66 that the left seat back 22is forwardly tipped, a warning sound is emitted by the warning buzzer.Accordingly, the driver can avoid traveling with the left seat back 22tipped forward.

Because the various mechanisms operate consecutively under the controlof the control unit 36 like this, stowing and returning of the seat canbe carried out just by operating the seat operating button 26.

Although in the embodiment described above an example was describedwherein an operation of rotating the seat cushion 21 from the stowedstate of the seat to a forwardly tipped state is carried out,alternatively, in a return to sitting step of returning the folded seatback 22 and the seat cushion 21 from the stowed state to a sittingstate, the lock mechanism 46 of the left reclining mechanism 40 of theseat back 22 may be unlocked at a position where the seat cushion 21 hasswung to a predetermined angle, for example 50°, and the motor driveforce then applied only to the seat cushion 21.

In this connection, next, an example of this kind of operation from astowed state to a sitting return state will be described, on the basisof the flow chart shown in FIG. 40 and of FIG. 38A, FIG. 38B and FIG.41A through FIG. 41C.

ST460: It is determined whether or not the return switch 38 is ON. Asshown in FIG. 41A, with the seat back 22 and the seat cushion 21 foldedand stowed in the floor recess 16, the return operation part 26 b of theseat operating part 26 is pushed with a finger. This operation of thereturn operation part 26 b turns ON the return switch 38.

ST461: It is determined whether or not the shift position is the Parkposition. When the shift position is not the Park position, processingends immediately. When the shift position is the Park position,processing proceeds to ST462.

ST462: It is determined whether or not the parking brake is ON. When theparking brake is OFF processing ends. When the parking brake is ON,processing proceeds to ST463.

ST463: A signal from the tailgate switch 378 shown in FIG. 30 isreceived.

ST464: It is determined whether or not the tailgate 146 shown in FIG.41A is open. When the tailgate 146 is not open, processing endsimmediately. When the tailgate 146 is open, processing proceeds toST465.

ST465: The drive motor 55 of the swinging means 30 shown in FIG. 3 isdriven to rotate in the return direction.

ST466: When the detection value detected by the seat cushion positionsensor 384 shown in FIG. 30 has reached 50°, the lock mechanism 46 isunlocked.

ST467: As a result of this unlocking, as shown in FIG. 41B, when theangle made by the seat cushion 21 and the floor 12 has become 50°, theseat back 22 falls downward away from the seat cushion 21 under its ownweight. Then, it is determined whether or not the motor current value isabove a predetermined value. When the motor current value is below thepredetermined value, processing proceeds to ST468, and the drive motor55 continues driving.

When the motor current value is above the predetermined value,processing proceeds to ST469.

ST469: When the motor current value is above the predetermined value asmentioned above, a stop signal is outputted to the drive motor 55 andthe drive motor 55 stops.

ST470: Then, a detection value from the seat cushion position sensor 384is received.

ST471: It is determined whether or not the value from the seat cushionposition sensor 384 is below a predetermined value (or example 30°) ofthe kind shown in FIG. 37. When it is above the predetermined value,processing ends immediately. When it is below the predetermined value,processing proceeds to ST472.

ST472: If it is below the predetermined value, a signal is outputted tooperate the warning buzzer 385, and the warning buzzer 385 for exampleemits a warning sound ten times intermittently.

ST473: As a result of the drive motor 55 continuing to drive in ST468,from the state shown in FIG. 38A, the latch 136 is caused by the striker142 to turn counterclockwise about the latch pin 137, and the latchswitch 62 turns OFF.

ST474: It is determined whether or not the lock switch 63 is OFF.

After it has been determined that the latch switch 62 is OFF in ST473,as shown in FIG. 38B the ratchet 138 returns to its initial position andthe lock switch 63 turns OFF, and processing proceeds to ST475.

ST475: When the lock switch 63 turns OFF, the rotation of the drivemotor 55 stops. As a result of the stopping of the rotation of the drivemotor 55, as shown in FIG. 41C, the rear seat 15 becomes ready forsitting in.

Thus, after the rear seat 15 has been returned to a sitting position bythe drive motor 55, because the seat back 22 is in position for sittingin, the work of pulling the seat back 22 upright by hand is unnecessary.

INDUSTRIAL APPLICABILITY

By making a system for stowing a rear seat in a floor recess formedbehind it electric, the effort of the seat stowing task is reduced. Thusthe invention is highly expedient for use in automotive vehicles and isuseful.

1. An electric stowing system for a vehicle seat for folding a seat backagainst a seat cushion and swinging the seat cushion and the seat backtogether and stowing them in a floor recess positioned behind the seat,the system comprising: seat back forward-tipping means for automaticallytipping the seat back forward to fold it against the seat cushion;swinging means for automatically swinging the forwardly tipped seat backand the seat cushion as one and stowing them in the floor recess; and acontrol unit for controlling the operation of the seat backforward-tipping means and the swinging means.
 2. An electric stowingsystem according to claim 1, wherein in returning the seat stowed in thefloor recess to a sitting state, at a position where the seat cushionhas swung to a predetermined angle a reclining lock of the seat backforward-tipping means is unlocked and a motor drive force is made to actonly on the seat cushion.
 3. An electric stowing system according toclaim 1, wherein it further comprises a seat operating switch forordering operation of the seat back forward-tipping means and theswinging means, and the seat operating switch is disposed behind theseat cushion.
 4. An electric stowing system according to claim 1,wherein the control unit controls the seat cushion and the seat back tobe operated automatically on the conditions that an automatictransmission of the vehicle is in a Park position, or a parking brake isoperating, and a tailgate is open.
 5. An electric stowing systemaccording to claim 1, wherein the seat back forward-tipping means isincorporated into the seat back or the seat cushion.
 6. An electricstowing system according to claim 1, characterized in that wherein thecontrol unit is incorporated into a central part of the seat cushion,outside of seating positions.
 7. An electric stowing system according toclaim 6, wherein it further comprises a dome-shaped cover member forcovering an upper face of the control unit, wherein the cover member isincorporated into the seat cushion.
 8. An electric stowing systemaccording to claim 7, wherein a buckle for fastening a seat belt forpassenger protection is disposed behind the cover member.
 9. An electricstowing system according to claim 7, wherein the cover member has in itsfront end an opening through which can pass at least one harnessextending from the control unit.
 10. An electric stowing systemaccording to claim 1, wherein it further comprises a seat operatingswitch for stowing a seat made up of the forwardly tipped seat back andthe seat cushion in the floor recess, and the seat operating switch isdisposed behind the rearmost seat and in the vicinity of the opening ofthe tailgate of the vehicle.
 11. An electric stowing system according toclaim 10, wherein the seat operating switch causes the operation ofstowing the seat to proceed only while its ON state is maintained. 12.An electric stowing system according to claim 10, wherein when withinthe range of swing of the seat the seat has stopped, a warning isprovided for a predetermined time.
 13. An electric stowing systemaccording to claim 10, wherein it further comprises a warning devicefor, when the seat cushion is not locked to the floor, warning that itis not locked, and the warning device is provided on the driver's side.14. An electric stowing system according to claim 13, wherein thewarning device is an indicator.
 15. An electric stowing system accordingto claim 13, wherein the warning is provided when the seat is at anangle to the floor such that it can be sat upon.
 16. An electric stowingsystem according to claim 10, wherein it further comprises a device forproviding a warning sound when the seat back is in a forwardly tippedstate.
 17. An electric stowing system according to claim 10, wherein theswinging means comprises a drive motor, and a warning is provided whenthe motor current value of the drive motor is above a predeterminedvalue.
 18. An electric stowing system according to claim 17, wherein acoupling part of the drive motor has a slip clutch.
 19. An electricstowing system according to claim 1, wherein the seat backforward-tipping means comprises: a reclining mechanism, having a springfor urging the seat back in a forward-tipping direction, which turnsabout a pivot shaft of the seat back; and unlocking means for unlockingthe reclining mechanism.
 20. An electric stowing system according toclaim 19, wherein the reclining mechanism has unlocking means forunlocking the reclining mechanism manually.
 21. An electric stowingsystem according to claim 19, wherein a one-way damper is providedbetween the seat cushion and the seat back so that a damper functionacts with respect to the forward tipping direction of the seat back butthe damper function does not act with respect to the return direction.